This invention relates generally to portable greenhouses, and cages for supporting plant branches and more particularly to an inexpensive multi-purpose structure that operates as a portable greenhouse in a first configuration and is convertable to a second configuration to operate as a plant cage.
Many different types of apparatus are used to help plants through their different stages of development. To protect plants from dying in their initial growing stage, they must be protected from harsh environmental conditions. For example, in the winter, it is often necessary to cover the plant or grow the plant inside a greenhouse to protect it from frost and cold winds. However, as the plant continues to grow and the weather becomes more temperate, the plant protection is no longer required. It is then necessary to support the branches or vines of the plant above the ground. This increases the exposure of the plant foliage to sun and rain, and also keeps the vines away from slugs and other infestations.
To prevent having to buy and install two different structures, it would be advantageous to use the same structure for both a greenhouse and a cage for hanging plant branches. Most structures, however, can not perform both functions. In addition, the most effective structure for a greenhouse is not necessarily the most effective structure for supporting plant branches. For example, a greenhouse should be designed so that it effectively protects the plant from harsh environmental conditions. It should also be sturdy enough not to be blown over or destroyed by wind and other conditions. On the other hand, a plant cage should be dimensioned to allow maximum exposure of the plant to sun and rain while maintaining a high degree of stability. In addition, the decision made by a gardener whether to plant, and the decision on what types of vegetables to plant, change from year to year. Thus, a gardener may need different sized greenhouses and plant supports each year. Alternatively, a greenhouse and plant support may only be needed for a single growing season. The structure, therefore, should be inexpensive enough to be disposed of after a single use.
U.S. Pat. No. 1,025,073 to Ragan illustrates a cone shaped wire structure for protecting a plant from sun and frost. The structure, however, can not be used as a plant cage, since there is insufficient space at the top of the cage to allow for additional plant growth. In addition, the circular members of the cage slope downward. This would cause the branches of a plant to slide down on top of each other preventing maximum exposure of the plants foliage to sun and rain.
U.S. Pat. No. 2,009,867 to Ball illustrates a trellis that can also be covered with a netting to provide protection of the plant from insects. The netting can then be removed from the trellis to provide support for hanging plant branches. The design of the structure, however, prevents it from being effective as both a greenhouse and plant support. For example, the wire structure maintains the same diameter throughout and has a separate top cover. The flat top makes the cage more susceptible to collapsing from the weight of snow and to being tipped over from animals that may try to perch on top of the structure.
Since the bottom of the cage is the same diameter as the top, it is more likely to be blown over by the wind. If the trellis in Ball were to effectively function as a greenhouse, it must be covered with some insulative material other than netting. The covering, however, increases the structure's wind resistance. Since the overall surface area in the Ball structure is greater than the surface area of a conical structure of the same height, the Ball structure is more likely to be blown over. Thus, the legs of the structure in Ball must be longer for deeper insertion into the ground and the cage must be made out of a heavier gauge wire to provide more support.
The trellis in Ball also does not provide the most effective support for hanging plant branches. Since the cage is the same diameter throughout, it is more difficult for the smaller branches at the bottom of the plant to reach the bottom rings of the structure. In addition, the structure doesn't expand outward from the base. This restricts outward plant growth, preventing maximum exposure of the plant to sun and rain. The trellis also comprises two separate pieces, (i.e., the cage and the cover). Separate components increase the cost of manufacture and increase the chances of losing a piece when not in use.
In a garden where multiple plant cages are used, the strength of each cage is increased by wiring the cages together. If the means for connecting each cage together was an integral part of the cage itself, it would eliminate the chance of losing parts and increase the cohesive strength of the overall structure. However, if the cages are placed too close to each other, the branches and roots of each plant will intertwine, preventing either plant from growing to its maximum potential. Thus, placing the cylindrical plant cage of Ball next to another similar cage could put their associated plants too close together. Since multiple plant cages are typically used in a garden, a significant amount of space is required for storage. Therefore, a superior plant cage/greenhouse structure would also be capable of being stacked.
Accordingly, a need exists for a low cost dual purpose greenhouse/plant cage that provides maximum support and the best possible growing. environment for a plant.